Excitonic spectrum of the ZnO/ZnMgO quantum wells

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Semiconductors

DOI:https://doi.org/10.1134/S1063782611060042· OSTI ID:22004794

Toropov, A A; Ivanov, S V ^[1]; El-Shaer, A; Bakin, A; Waag, A ^[2]

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1. Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)
2. TU Braunschweig, Institute of Semiconductor Technology (Germany)

Excitonic spectrum of the wurtzite ZnO/Zn{sub 1-x}Mg{sub x}O quantum wells with a width on the order of or larger than the Bohr radius of the exciton has been studied; the quantum wells have been grown by the method of molecular beam epitaxy (with plasma-assisted activation of oxygen) on substrates of sapphire (0001). Low-temperature (25 K) spectra of photoluminescence excitation (PLE) have been experimentally measured, making it possible to resolve the peaks of exciton absorption in the quantum well. The spectrum of excitons in the quantum well is theoretically determined as a result of numerical solution of the Schroedinger equation by the variational method. The value of elastic stresses in the structure (used in calculations) has been determined from theoretical simulation of measured spectra of optical reflection. A comparison of experimental data with the results of calculations makes it possible to relate the observed features in the PLE spectra to excitons, including the lower level of dimensional quantization for electrons and two first levels of holes for the A and B valence bands of the wurtzite crystal. The values of the electron and hole masses in ZnO are refined, and the value of the built-in electric field introduced by spontaneous and piezoelectric polarizations is estimated.

• OSTI ID: 22004794
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 6 Vol. 45; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
CRYSTALS
ELECTRIC FIELDS
EXCITATION
EXCITONS
MOLECULAR BEAM EPITAXY
NUMERICAL SOLUTION
OPTICAL REFLECTION
PEAKS
PHOTOLUMINESCENCE
PIEZOELECTRICITY
PLASMA
POLARIZATION
QUANTUM WELLS
SAPPHIRE
SCHROEDINGER EQUATION
SIMULATION
SPECTRA
SUBSTRATES
ZINC OXIDES